ComboBox Option ( Add , Set , Get )

* Add 1 : 수동 추가 

public class ComboboxItem
{
    public string Text { get; set; }
    public object Value { get; set; }

    public override string ToString()
    {
        return Text;
    }
}
 
private void Test()
{
    ComboboxItem item = new ComboboxItem();
    item.Text = "Item text1";
    item.Value = 12;

    comboBox1.Items.Add(item);

    comboBox1.SelectedIndex = 0;

    MessageBox.Show((comboBox1.SelectedItem as ComboboxItem).Value.ToString());
}

* Add 2 : DataBase 연동

private void frmCityMapping_Load(object sender, EventArgs e) {
  string ConnectionString = "server=아이피;database=데이터베이스;uid=아이디;pwd=패스워드;"; 
  try {
    SqlConnection dbConn = new SqlConnection(ConnectionString);
    dbConn.Open();
    SqlCommand cmd = new SqlCommand("SELECT splyCd,splyEnm FROM tblsupply order by splyEnm", dbConn);
     
    using(var myReader = cmd.ExecuteReader()) {
      while (myReader.Read()) {
        splyCd.Items.Add(new comboboxItem(myReader["splyEnm"].ToString(), myReader["splyCd"].ToString()));
      }
      splyCd.SelectedIndex = 0;
    }
     
    cmd.CommandText = "SELECT nationCd,nationENm FROM tblNation order by nationENm";
    using(var myReader = cmd.ExecuteReader()) {
      while (myReader.Read()) {
        nationCd.Items.Add(new comboboxItem(myReader["nationENm"].ToString(), myReader["nationCd"].ToString()));
      }
      nationCd.SelectedIndex = 0;
    }
    dbConn.Dispose();
    dbConn.Close();
  } catch (Exception b) {
    MessageBox.Show(b.ToString());
  }
}
 
 
public class comboboxItem {
    public string Text {
        get;
        set;
    }
    public object Value {
        get;
        set;
    }
 
    public override string ToString() {
        return Text;
    }
    public comboboxItem(string text, object value) {
        Text = text;
        Value = value;
    }
}

* Set : 값 지정하기

nationCd.Text = "KR";

* Get : 선택 값 가져오기 

comboboxItem item;
item = (comboboxItem)nationCd.SelectedItem;
string nationValue = item.Value.ToString();